Question on migration from fas2020 to fas2240-2

We purchased a new FAS2240-2 with 24 450gb SAS disks and I have a question for migration from my FAS2020 with external shelf. Is it a good idea to snapmirror the root volume from my 2020 to the new 2240 so all my settings stay in place for my environment? I am running 7.3.6 on the FAS2020 device and 8.1.1 7-mode on the FAS2240-2 device. I am looking for advice on what my best path for this migration would be. I appreciate any help in advance.